Before a scanned image is printed out, an image forming apparatus, such as a copying machine and a multifunction printer, often displays a preview of a document image shown in the scanned image that has been image-processed in accordance with a processing condition set by a user. In a case where a plurality of documents are read, each of the documents may be print-previewed one by one, or the plurality of documents may be print-previewed collectively. The processing condition includes: a sort of a document; a print density; a ratio in enlarging/reducing processing; single-sided printing or two-sided printing; a binding margin size; and the like.
Patent Literature 1 discloses an image forming apparatus in which a preview of a document image is displayed so that a user can (i) check the document image and (ii) input command to carry out a rotation processing and a rotation angle. The image forming apparatus displays a checking icon for accepting a command to carry out rotation processing and setting of a rotation angle. A user inputs a command to carry out rotation processing and a rotation angle by clicking the checking icon. The rotation angle can be set to 0°, 90°, 180°, and 270°. According to the image forming apparatus disclosed in Patent Literature 1, a rotation direction is a clockwise direction. Specifically, if a user wants to rotate an image (scanned image), in which a document image is shown, at a right angle in a clockwise direction, the rotation angle is set to 90°, and if the user does not want to rotate the image, the rotation angle is set to 0°.
Patent Literature 1 teaches that when the image forming apparatus receives a command to carry out the rotation processing from a user, the image forming apparatus carries out the rotation processing with respect to an image (scanned image) in which a document image is shown, and then again displays a preview of the image after the rotation processing. Further, Patent Literature 1 teaches that the image forming apparatus displays a list of a plurality of documents images, and carries out the rotation processing collectively with respect to the plurality of documents images. Furthermore, Patent Literature 1 teaches that the image forming apparatus automatically determines a page orientation of a document image, and then displays a preview of the document image that has been rotated based on the page orientation automatically determined.